SUMMARYClassification, by agglutinogens, of 634 isolates ofBordetella pertussiscollected from 1941 to 1968 in Great Britain demonstrated that a change from a predominantly 1,2,0,4 serotype (75% of those examined during 1941–4) to a predominantly 1,0,3,0 serotype (73% of those examined during 1966–8) occurred sometime after 1953. Furthermore, evidence from the examination of isolates collected between 1941 and 1953 suggests that the change may have been gradual. Isolates of serotype 1,2,3,4 made up 20–30% of the total of our cross-country selection for the periods 1941–4, 1946–9, 1950–3 and 1966–8, but over shorter periods in individual areas the percentage varied from negligible to as high as half of those isolated. Results from other countries show a similar drift towards a 1,0,3 serotype but more often from a 1,2,3 than from 1,2,0 serotype.The value, in epidemiological studies, of extended information obtained by monospecific typing sera to all six, rather than only two or three agglutinogens, and confirmation of the results by agglutinin production is demonstrated: for instance not all 1,0,3 isolates were identical.
SUMMARYWhen mice were injected intracerebrally with doses of Bordetella pertussis vaccine greater than 5 ImD 50 and challenged intracerebrally 14 days later with virulent B. pertussis there was an immediate reduction in the numbers of organisms.An analysis of this in vivo bactericidal effect has shown that large doses of an unrelated vaccine, Salmonella typhosa, equivalent in cell mass to about 50 ImD 50 of B. pertussis vaccine can achieve this effect, so for such doses the effect must be partly non-specific. This action is not maintained and so is not ultimately protective. Local immunoglobulin was also demonstrable 14 days after 300 ImD50 of B. pertussis vaccine but following smaller doses of 10-20 ImD 50 it could not be found until after the mice had been infected and the blood-brain barrier impaired.A similar immediate reduction in the numbers of infecting organisms inoculated 1 day after vaccination has been shown to follow very small, non-protective doses of vaccines unrelated to B. pertussis and to be achieved with lipopolysaccharide and endotoxin isolated from B. pertussis. Brains were not sterilized and only in mice receiving protective B. pertussis vaccine was the lowering of infection maintained beyond 2 days and the brains eventually sterilized.The antibody passively protecting mice against intracerebral infection was found in the 19 S and 1 1 S globulin fractions of the serum of once-vaccinated mice and in the 11 S and 7 S fractions of the serum of rabbits and ascitic fluid of mice receiving repeated doses of vaccine. The IgM probably eliminated infections by immediate sterilization but had to be present locally to do so since it was unable to pass from the circulation into the brain, and was therefore inactive when injected intraperitoneally. The IgA and IgG were not so restricted and both the 11 S and 7 S globulins were capable of exerting an immediate suppressive effect on infecting organisms. The 7 S globulin was also capable of a maintained or delayed suppressive effect.Lymphocytes from fully protected once-vaccinated mice, transferred 2-3 weeks after intraperitoneal vaccination, were able to confer some protection when injected intraperitoneally or intracerebrally into recipient mice infected 2 weeks after transfer. Homologous, non-concentrated antiserum from once-vaccinated
SUMMARYStrains ofBordetella pertussisin which all the organisms contain agglutinogens 1 and 3 or 1, 2 and 4 are easy to identify as serotypes 1,0,3,0 and 1,2,0,4 respectively; and similarly, stable strains of serotype 1,0,3,4 are occasionally found. During repeated subcultures, passagein vivo, and lyophilization and preservation for many years, these serotypes do not change. Mixing 1,0,3,0 and 1,2,0,4 serotypes and culturing them togetherin vivoandin vitroproduces cultures from which organisms of the same two serotypes can be isolated.In contrast, strains which type as 1,2,3,4 are often a heterogeneous group. We have attempted to classify these as 'stable', 'variable' and 'mixed' cultures. Some strains comprise organisms all of which contain the four agglutinogens and are as easy to type as the strains described above. These we have called 'stable' 1,2,3,4 strains. Other 1,2,3,4 strains are made up of colonies possessing all four agglutinogens, as shown by agglutinin production, but in amounts varying from day to day so that direct typing is inconsistent. These we have called 'variable' 1,2,3,4 strains. The last category, 'mixed', is made up of organisms most of which give rise to stable 1,2,3,4 cultures; a few of the component organisms, however, have one or two of the four agglutinogens missing. The importance of the 'variable' cultures is emphasized for work on apparent change of serotype, e.g. during infection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.